Figure 1 - full size

 

Figure 1.
Fig. 1. (A) Organization of the Ori1 replication origin in A. pernix. The four ORB sequences are located on either side of the DUE. The sequence of the 5'-to-3' ("top") strand of ORB4 is shown. (B) Overall structure of the ORC1-DNA complex. (C) Contacts between the AAA^+ domain and DNA. Thr^122 (T122) (21) contacts the Gd18-Cd5 base pair, L124 main chain oxygen contacts Gd19, and E128 contacts Gd20 via a water molecule. Residues T103, R106, G123, and R132 make direct interactions with the phosphodiester backbone on either side of the minor groove. (D) Insertion of the wing of the WH domain into the DNA minor groove widens it by 5 Å. Residues S366, G368, G371, and K372 interact directly with bases Td17, Gd18, and Gd19 of the complementary strand. G368, G371, K372, and T373 also interact with the DNA backbone on both sides of the minor groove. (E) Insertion of the recognition helix of the WH domain into the major groove. R345 makes a base-specific interaction with Gd10. Residues T343, R346, S348, and R374 contact the DNA phosphate backbone. The R346 side chain is stabilized in a noncanonical conformation by a salt bridge interaction with E353, which enables it to bind the DNA phosphate backbone. In the same way, interaction between S352 and R374 brings the arginine side chain close to the DNA backbone.

The above figure is reprinted by permission from the AAAs: Science (2007, 317, 1213-1216) copyright 2007.